1,324 research outputs found

    Aspect ratio dependence of heat transport by turbulent Rayleigh-B\'{e}nard convection in rectangular cells

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    We report high-precision measurements of the Nusselt number NuNu as a function of the Rayleigh number RaRa in water-filled rectangular Rayleigh-B\'{e}nard convection cells. The horizontal length LL and width WW of the cells are 50.0 cm and 15.0 cm, respectively, and the heights H=49.9H=49.9, 25.0, 12.5, 6.9, 3.5, and 2.4 cm, corresponding to the aspect ratios (ΓxL/H,ΓyW/H)=(1,0.3)(\Gamma_x\equiv L/H,\Gamma_y\equiv W/H)=(1,0.3), (2,0.6)(2,0.6), (4,1.2)(4,1.2), (7.3,2.2)(7.3,2.2), (14.3,4.3)(14.3,4.3), and (20.8,6.3)(20.8,6.3). The measurements were carried out over the Rayleigh number range 6×105Ra10116\times10^5\lesssim Ra\lesssim10^{11} and the Prandtl number range 5.2Pr75.2\lesssim Pr\lesssim7. Our results show that for rectangular geometry turbulent heat transport is independent of the cells' aspect ratios and hence is insensitive to the nature and structures of the large-scale mean flows of the system. This is slightly different from the observations in cylindrical cells where NuNu is found to be in general a decreasing function of Γ\Gamma, at least for Γ=1\Gamma=1 and larger. Such a difference is probably a manifestation of the finite plate conductivity effect. Corrections for the influence of the finite conductivity of the top and bottom plates are made to obtain the estimates of NuNu_{\infty} for plates with perfect conductivity. The local scaling exponents βl\beta_l of NuRaβlNu_{\infty}\sim Ra^{\beta_l} are calculated and found to increase from 0.243 at Ra9×105Ra\simeq9\times10^5 to 0.327 at Ra4×1010Ra\simeq4\times10^{10}.Comment: 15 pages, 7 figures, Accepted by Journal of Fluid Mechanic

    Tetra­kis(1-phenyl-1H-imidazole-κN 3)bis­(thio­cyanato-κN)nickel(II)

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    The title compound, [Ni(NCS)2(C9H8N2)4], crystallizes with two independent half-mol­ecules in the asymmetric unit and the NiII ions situated on centres of symmetry. In both independent mol­ecules, the NiII ion displays a compressed octa­hedral environment formed by four N atoms from the 1-phenyl-1H-imidazole ligands, which define the equatorial plane, with a mean Ni—N distance of 2.119 (11) Å, and two axial N atoms from two NCS− anions, with a mean Ni—N distance of 2.079 (7) Å. The crystal packing exhibits weak inter­molecular S⋯S contacts of 3.411 (2) Å

    Impact of Sucrose Addition on the Physiochemical Properties and Volatile Compounds of “Shuangyou” Red Wines

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    “Shuangyou,” a Vitis amurensis Rupr. variety, is widely cultivated in northeastern and western China. Its berries have high acidity and low sugar content. In this study, different proportions of sucrose were added to the must samples during fermentation to investigate the effect of sugar on the physicochemical properties and volatile compounds of “Shuangyou” wines. The addition of sucrose significantly improved yeast growth and alcohol production, altered the color qualities, and slightly decreased titratable acidity during fermentation. The highest tested proportion of added sucrose resulted in the highest maximum yeast counts and final ethanol concentrations. Moreover, 37 volatile compounds (esters, alcohols, fatty acids, ketones, and aldehydes) were identified and quantified by solid-phase microextraction with gas chromatography-mass spectrometry. The concentrations of these compounds were correlated with the addition of sucrose. Furthermore, the addition of 100 g/L sucrose was sufficient for improving the concentrations of the aromatic compounds. The increase in ester, alcohol, and fatty acid concentration led to a positive OAVs impact (odor activity value > 1) at the end of fermentation

    TRACE: 5D Temporal Regression of Avatars with Dynamic Cameras in 3D Environments

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    Although the estimation of 3D human pose and shape (HPS) is rapidly progressing, current methods still cannot reliably estimate moving humans in global coordinates, which is critical for many applications. This is particularly challenging when the camera is also moving, entangling human and camera motion. To address these issues, we adopt a novel 5D representation (space, time, and identity) that enables end-to-end reasoning about people in scenes. Our method, called TRACE, introduces several novel architectural components. Most importantly, it uses two new "maps" to reason about the 3D trajectory of people over time in camera, and world, coordinates. An additional memory unit enables persistent tracking of people even during long occlusions. TRACE is the first one-stage method to jointly recover and track 3D humans in global coordinates from dynamic cameras. By training it end-to-end, and using full image information, TRACE achieves state-of-the-art performance on tracking and HPS benchmarks. The code and dataset are released for research purposes.Comment: Project page: https://www.yusun.work/TRACE/TRACE.htm

    Theoretical analysis for the apparent discrepancy between pbarp and pp data in charged particle forward-backward multiplicity correlations

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    The strength of charged particle forward-backward multiplicity correlation in pbar+p and p+p collisions at s^1/2 = 200 GeV is studied by PYTHIA 6.4 and compared to the UA5 and STAR data correspondingly. It is turned out that a factor of 3-4 apparent discrepancy between UA5 and STAR data can be attributed to the differences in detector acceptances and observing bin interval in both experiments. A mixed event method is introduced and used to calculate the statistical correlation strength and the dynamical correlation strengths stemming from the charge conservation, four- momentum conservation, and decay, respectively. It seems that the statistical correlation is much larger than dynamical one and the charge conservation, four-momentum conservation and decay may account for most part of the dynamical correlation. In addition, we have also calculated the correlation strength by fitting the charged particle multiplicity distribution from PYTHIA to the Negative Binomial Distribution and found that the result agrees well with the correlation strength calculated by mixed events.Comment: 5 pages, 4 figure

    Improving the Message-ciphertext Rate of Lewko\u27s Fully Secure IBE Scheme

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    In Eurocrypt 2012, Lewko presented a fully secure IBE scheme in the prime order setting based on the decisional linear assumption. We note that some random factor involved in the ciphertext can further be used to hide yet another message , and get a new fully secure IBE scheme with better message-ciphertext rate. Similar to Lewko\u27s scheme, we use dual pairing vector space in prime order bilinear groups to simulate the canceling and parameter hiding properties of composite order settings. The security of our scheme is based on the subspace assumption, which can be reduced to the decisional linear assumption. We employ the dual system encryption technique in our security proof

    Apresiasi Masyarakat Terhadap Tradisi Lisan Permainan Rakyat Jaran Kepang Di Kanagarian Simalidu Kecamatan Koto Salak Kabupaten Dharmasraya

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    The perposes of this researeh are to describe and the explain the appreciation of society in kanagarian Simalidu Kecamatan Koto Salak Kabupaten Dharmasraya. West Sumatra to the Jaran Kepang. The research is using the descriptive methade and the of this research is qualitative the issues that describe is type the appreciation and the acceptance of the society to Jaran Kepang in Kanagarian Simalidu Kecamatan Koto Salak Kabupaten Dharmasraya. That obtainable through the questionnaire and interview that using by the instrument in this research. The accumulation technique of data that using here are: (1) the observation to searching the informan that requires in the research, (2) give the questionnaire that contain same questions that have to be answered by the society in Kanagarian Simalidu Kecamatan Koto Salak Kabupaten Dharmasraya, (3) The structural interview, by using some questions to the informans based an the research, (4) record, by recorded oral data that express by the informans, (5) note, by kating all the informan that has bean obtained from the observation the interview, and the recard

    浅析中药学与民族药学对木香的临床应用异同

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    Costusroot is commonly used in traditional medicine,Mongolian medicine,Tibetan medicine,Dai medicine and Uighur medicine. We discuss similarities and differences in clinical applications of costusroot in traditional medicine,Mongolian medicine,Tibetan medicine,Dai medicine and Uighur medicine, from aspects of its property and flavor,functions and indications ,and clinical applications. For sake of retaining their own features, the authors intended to integrate the essences of the two, broaden its clinical applications, make costusroot to play its role fully and fully understand the natural medicinal plants ,which is more conducive to modernize the traditional medicine.木香是中、蒙、藏、傣以及维医药学的常用药。本文从木香的性味、功效主治及临床应用等方面,比较探讨木香在中医药学、蒙医药学、藏医药学、傣医药学及维医药学中的临床应用异同,希冀在保留各自特色的基础上,相互借鉴,拓宽临床应用,使之发挥其更全面的作用,同时全面认识自然界药用植物,更有利于促进中药现代化
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